Wearable mobile device and method of measuring biological signal with the same

ABSTRACT

A wearable mobile device and a method of detecting a biosignal with a wearable mobile device are provided. A method of detecting a biosignal with a wearable mobile device involves determining whether a wearable mobile device is closely attached to a user; and providing a biosignal-based service in response to the wearable mobile device being determined to be closely attached to the user.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit under 35 USC 119(a) of Korean PatentApplication No. 10-2013-0144550 filed on Nov. 26, 2013, in the KoreanIntellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND

1. Field

The following description relates to a wearable mobile device and amethod of detecting a biosignal with a wearable mobile device.

2. Description of Related Art

The widespread use of smart mobile terminals is resulting in thedevelopment of new forms of wearable mobile devices as well asdiversification of such devices.

Some wearable mobile devices are equipped not only with a function ofdisplaying information about a mobile terminal, but also with a functionof detecting a biological signal from a user to monitor the healthconditions of the user. Wearable mobile devices that measure biosignalsare implemented in various configurations. For example, one type of suchdevices is a watch-type device that may monitor a heart rate of the userwearing the device using a photoplethysmography (PPG) sensor.

To detect a biological signal from the body of the user, a sensor in awatch-type device needs to be attached close to the skin of the user.However, to achieve the close contact between the sensor and the skin,the device may be positioned unnecessarily and excessively tight aroundthe skin. Accordingly, a user wearing such a wearable mobile device mayfeel that his or her wrist or body part wearing the device isconstricted by the device.

Furthermore, the constriction experienced by the user may intensify dueto the fact that the wearable mobile device is closely attached to theskin at all times, even when the device is not detecting the biologicalsignals from the user. Accordingly, it is desirable to produce awearable mobile device that accurately detects biological signals whileproviding comfort to the user.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

In one general aspect, there is provided a method of measuring abiosignal, the method comprising determining whether a wearable mobiledevice is closely attached to a user, and providing a biosignal-basedservice in response to the wearable mobile device being determined to beclosely attached to the user.

The providing may involve executing a program for sensing a biosignalfrom the user or a program that uses the sensed biosignal, and providinga result from the executed program as the biosignal-based service.

The determining may involve measuring a range or a position at which thewearable mobile device contacts the user, and determining that thewearable mobile device is closely attached to the user in response tothe measured range satisfying a predetermined standard value or inresponse to the measured position corresponding to a predetermined skinarea of the user.

In another general aspect, there is provided a method of using awearable mobile device, the method involving attaching a braceletcomprising a sensor to an user, determining whether the sensor isclosely attached to the user based on a movement of the bracelet duringattachment to the user, and sensing the biosignal from the user byactivating the sensor in response to a determination that the sensor isclosely attached to the user.

The determining may involve placing an analog front end of the sensor incontact with a body of the user, and determining that the bracelet isclosely attached to the user in response to the analog front end beingnot in a leadoff state.

The determining may involve sending a microcurrent to a body of the userthrough the analog front end of the sensor, and determining that thebracelet is closely attached to the user in response to an impedancemeasured based on a return of the sent microcurrent satisfying apredetermined value.

In the general aspect of the method, the bracelet may further include anadditional sensor for determining whether the bracelet is closelyattached to the user, and the determining may involve determining thatthe bracelet is closely attached to the user in response to theadditional sensor entering an operating state based on a body positionat which the bracelet is attached to the user.

The sensing may involve identifying an activated sensor based on a bodyposition at which the bracelet is closely attached to the user, andsensing the biosignal by the identified sensor.

The general aspect of the method may further include, in response todetermining that the bracelet is closely attached to the user, executinga program associated with the biosignal or adjusting a systemenvironment to be a predetermined value.

The general aspect of the method may further include outputting a resultof the determining of whether the bracelet is closely attached to theuser.

In another general aspect, a wearable mobile device includes a braceletconfigured to be attached to a user by surrounding a body of the user, adeterminer configured to determine whether the bracelet is closelyattached to the user based on a movement of the bracelet duringattachment to the user, and a sensor unit including sensors configuredto sense a biosignal from the user subsequent to activation in responseto the determiner determining that the bracelet is closely attached tothe user.

An analog front end in the sensors may be in contact with the body ofthe user, and the determiner may be configured to determine that thebracelet is closely attached to the user in response to the analog frontend being not in a leadoff state.

The analog front end in the sensors may be configured to send amicrocurrent to the body of the user, and the determiner may beconfigured to determine that the bracelet is closely attached to theuser in response to an impedance measured based on a return of the sentmicrocurrent satisfying a predetermined value.

The bracelet may further include an additional sensor for determiningwhether the bracelet is closely attached to the user, and the determinermay be configured to determine that the bracelet is closely attached tothe user based on a body position at which the bracelet is attached tothe user in response to the additional sensor entering an operatingstate.

The sensor unit may be configured to identify an activated sensor basedon a body position at which the bracelet is closely attached to the userand sense the biosignal by the identified sensor.

The general aspect of the device may further include a controllerconfigured to, in response to the bracelet being determined to beclosely attached to the user, execute a program associated with thebiosignal or adjust a system environment to be a predetermined value.

The general aspect of the device may further include an output unitconfigured to output a result of the determining of whether the braceletis closely attached to the user.

In a general aspect, a wearable mobile device includes a band portionconfigured to detachably attach the wearable mobile device to a user,the band portion comprising a sensing surface configured to contact askin of the user, a processor configured to determine a contact state ofthe sensing surface and the skin as at least one of: a close contactstate and a loose state, and a sensor unit comprising a biosignal sensorconfigured to sense a biosignal via the skin in response to theprocessor determining that the sensing surface is in a close contactstate.

The sensor unit may be configured to inactivate the biosignal sensor inresponse to the processor determining that the sensing surface is in aloose state.

The general aspect of the wearable mobile device may further include acontact detecting sensor disposed on the band portion, and the contactdetecting sensor may be configured to detect a signal used by theprocessor to determine the contact state of the sensing surface with theskin of the user.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram illustrating an example of a wearable mobiledevice.

FIG. 1B is a diagram illustrating another example of a wearable mobiledevice.

FIG. 2 is a diagram illustrating a configuration of an example of awearable mobile device.

FIGS. 3A and 3B are diagrams illustrating examples of methods ofdetermining whether a sensor is closely attached to a user.

FIG. 4 is a flowchart illustrating an example of a method of a wearablemobile device selectively using biosignals.

Throughout the drawings and the detailed description, unless otherwisedescribed or provided, the same drawing reference numerals will beunderstood to refer to the same elements, features, and structures. Thedrawings may not be to scale, and the relative size, proportions, anddepiction of elements in the drawings may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the systems, apparatuses and/ormethods described herein will be apparent to one of ordinary skill inthe art. The progression of processing steps and/or operations describedis an example; however, the sequence of and/or operations is not limitedto that set forth herein and may be changed as is known in the art, withthe exception of steps and/or operations necessarily occurring in acertain order. Also, descriptions of functions and constructions thatare well known to one of ordinary skill in the art may be omitted forincreased clarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will convey the fullscope of the disclosure to one of ordinary skill in the art.

To accurately detect a signal from the body of the user, a sensor of awearable mobile device needs to be positioned close to the skin.However, having a mobile device tightly attached to a body part maycause uncomfortable feeling of constriction. Further, having thewearable mobile device attached closely to the skin even when thebiological signals are not being detected may make it undesirable forthe user to wear the mobile device at all times.

An improved wearable mobile device that allows a close attachment to theskin while biosignals are detected, and allows a loose attachment whilebiosignals are not detected may improve the user experience. Further,the displayed content of the wearable mobile device may be furthercontrolled based on whether the biological signals are being detected orwhether the mobile device is in a close contact to detect the biologicalsignals, so that unnecessary information does not take up the limiteddisplay space.

A sensor unit described herein refers to a sensor or a set of sensorsthat may be attached to an object such as a body part of a user or atarget, and detects a signal generated from the object. The detectedsignal may include an electrocardiogram (ECG), a photoplethysmogram(PPG), an impedance, an electromyogram (EMG), or other biological signalassociated with the user. The sensor or the set of sensors included inthe sensor unit may refer to a PPG sensor, an EMG sensor, and the likethat may be used to monitor the contraction and relaxation of muscles ormay sense various types of biosignals. In addition to such sensors, thesensor unit may include an additional sensor such as, for example, atemperature sensor, a force sensor, and an illuminance sensor, that maybe used to determine whether a wearable mobile device is closelyattached to the user. When the wearable mobile device is closelyattached to the user, the wearable mobile device may be referred to asbeing in a close contact state. When the wearable mobile device isdetermined to be not closely attached even though the mobile device isattached to the user, the wearable mobile device may be determined to bein a loose state.

A bracelet may include the sensor unit that includes the sensor or theset of sensors. The bracelet may be detachably attached to a human body.The bracelet may be implemented in a variety of different format. Forexample, the bracelet may have the format of a ring-shaped structurethat may be attached to a user by allowing a hand of the user to passthrough the ring-shaped structure to position the ring-shaped structurearound the wrist of the user. In another example, the bracelet may havea semi-ring shape to be attached by allowing the wrist to pass throughan open portion of a ring. In another example, the bracelet may have ahinge shape to allow the wrist to pass through a ring by opening aportion of the ring and closing the opened portion of the ring after thewrist is positioned in the ring.

For example, when a ring-shaped bracelet is attached to an arm, which isthe target object, the sensor unit disposed in the bracelet may be usedto detect a biosignal generated from an arm muscle. In detecting abiosignal, the sensor unit may detect the biosignal generated from thearm muscle when the bracelet moves towards a forearm having a relativelygreater circumference and thereby, being closely attached to the arm.

Conversely, the sensor unit may suspend the detection of a biosignal inresponse to the bracelet moving towards the wrist having a relativelysmall circumference and thereby, being loosely attached to the arm.Thus, the sensor unit may selectively detect the biosignal based onwhether the bracelet is closely attached to the user or loosely attachedto the user.

A wearable mobile device described herein may provide a biosignal-basedservice by activating the sensor unit and allowing the sensor unit tosense a biosignal when the bracelet is determined to be closely attachedto the user.

The wearable mobile device may provide the biosignal-based service inresponse to a simple action of the user closely attaching the braceletto the body part without requiring an additional operation from theuser. For example, the user may use his or her hand to bring the sensorregion of the bracelet in firm contact with the skin underneath. Basedon the pressure, the wearable mobile device may activate the sensorunit, without pushing any button or manipulating any object in thedigital display screen. Thus, convenience may be further improved.

FIGS. 1A and 1B are diagrams illustrating examples of wearable mobiledevices 100 and 110.

Referring to FIGS. 1A and 1B, a wearable mobile device 100 of FIG. 1Aand a wearable mobile device 110 of FIG. 1B are implemented in a form ofa bracelet or a wrist watch that may be worn around a body part of auser to be attached to the user.

The wearable mobile devices 100 and 110 may include band portions 102and 112 configured to attach the wearable mobile devices 100 and 110 toa body part such as a wrist, sensor units 104 and 114 configured todetect a biosignal of the user via from the body part, and display units106 and 116 configured to provide visual user interface regarding abiosignal-based service to the user. The display units 106 and 116 maybe configured to display time or provide other services to the user inaddition to providing a biosignal-based service. Referring to FIG. 1B,the wearable mobile device 110 may include a gap 118 at which a portionof a ring that forms the bracelet is open. The gap 118 may allows a userto insert his or her wrist into the ring.

The band portions 102 and 112 may attach the wearable mobile devices 100and 110 to the user by surrounding the body part of the user. The bandportions 102 and 112 of the bracelet may include the sensor units 104and 114 and the display units 106 and 116, respectively, and obtain abiosignal and provide necessary information while attached to the user.

In an example, the band portions 102 and 112 may be composed of a hardmaterial. Thus, exteriors of the bracelets may not be easily deformed byan external force. When mounted on a wrist of the user, for example, thespace between the wrist and the band portions 102 and 112 may form a gapand allow the bracelet to loosely attach to the wrist. In an example,the band portions 102 and 112 may not permanently tighten the body ofthe user due to an elastic property of the band portions 102 and 112.Accordingly, a period of time during which the band portions 102 and 112are closely attached to the user and a period of time during which theband portions 102 and 112 are loosely attached to the user may beclassified in accordance with a service desired by the user.

In another example, the band portions 102 and 112 may be formed of aflexible material having elasticity, and selectively detect a biosignalfrom the user based on a transformation of the band portions 102 and 112induced by the elasticity. The band portions 102 and 112 may beclassified, based on a range or a position at which the band portions102 and 112 are attached to the user, the period of time during whichthe band portions 102 and 112 are closely attached to the user to allowthe sensors 104 and 114 to detect a biosignal and the period of timeduring which the band portions 102 and 112 are loosely attached to theuser to disallow detection of a biosignal by the sensors 104 and 114.

For example, when the band portions 102 and 112 are mounted on a wristof a user, the wearable mobile devices 100 and 110 may determine thatthe band portions 102 and 112 are not closely attached to the user.Conversely, when the band portions 102 and 112 are attached to the useris a forearm having a relatively greater circumference than the wrist,the wearable mobile devices 100 and 110 may determine that band portions102 and 112 are closely attached to the user. Also, when the range inwhich the band portions 102 and 112 are attached to the user exceeds apredetermined standard value, despite the user to which the bandportions 102 and 112 are attached being the wrist, the wearable mobiledevices 100 and 110 may determine that the band portions 102 and 112 areclosely attached to the user.

Referring to FIG. 1A, the band portion 102 may be implemented in a shapeof a ring to be attached to the use by allowing the hand of the user topass through the ring. Referring to FIG. 1B, the band portion 112 may beimplemented in a shape of a semi-ring including the gap 118. The bandportion 112 may further include a hinge (now shown) that may allow thebracelet to be attached to the wrist by closing the opened portion ofthe ring after the wrist passes through the gap 118.

The sensor units 104 and 114 may include at least one sensor that maydetect various types of biosignals from the user. The sensor units 104and 114 may obtain the biosignals from the user through the sensorduring the bracelets being closely attached to the user. The biosignalsdetected by the sensor units 104 and 114 may include an ECG, a PPG, animpedance, an EMG, and the like.

The display units 106 and 116 may provide a visual biosignal-basedservice generated in associated with the detected biosignals.

For example, when the biosignals detected by the sensor units 104 and114 are associated with heart rates, information on the heart rates atwhich a most amount of weight may be lost by aerobic exercise may be fedback to the displays 106 and 116 and displayed as the biosignal-basedservice.

For another example, when the biosignals detected by the sensor units104 and 114 are associated with the EMG, the displays 106 and 116 mayexecute, as the biosignal-based service, a program for controllingperipheral devices by a movement, for example, a hand gesture, of theuser.

For still another example, when the biosignals detected by the sensorunits 104 and 114 are associated with the impedance, information on acalculated amount of body fat may be fed back to the display units 106and 116 and displayed as the biosignal-based service.

The detecting of the biosignals and the providing of the biosignal-basedservice may be performed when the sensor units 104 and 114 are closelyattached to the user.

However, when the sensor units 104 and 114 are not closely attached tothe user, the detecting of the biosignals is suspended, and the displayunits 106 and 116 may provide a service to communicate with a connectedterminal, for example, displaying information on a smartphone, or aservice that is not directly related to the biosignals.

The wearable mobile devices 100 and 110 may further include anaccelerometer that may monitor a quantity of utilization of the wearablemobile devices 100 and 110. The display units 106 and 116 may visuallyprovide the monitored quantity of utilization when the sensor units 104and 114 and the band portions 102 and 112 of the bracelet are notclosely attached to the user.

The wearable mobile devices 100 and 110 may detect a biosignal byallowing the sensor units 104 and 114 to be closely attached to the userexclusively when the detection of the biosignal is necessary. Also, thewearable mobile devices 100 and 110 may selectively measure heart ratesduring an exercise period, measure an EMG to control a home electronicappliance by a gesture, or measure an impedance to authenticate theuser.

Thus, the wearable mobile devices 100 and 110 may be closely worn onskin of the user when detection of a biosignal is required, and beloosely worn when detection of the biosignal is not required.

The wearable mobile devices 100 and 110 may determine whether the bandportions 102 and 112 are closely attached to the user. In one example,the wearable mobile devices 100 and 110 may determine whether theportion of the band including the sensor units 104 and 114 arecontacting the skin or pressed against the skin of the user. Thewearable mobile devices 100 and 110 may determine whether a biosignal isto be measured based on a degree of contact between the sensor units 104and 114 and the skin of the user.

In an example, to determine whether the band portions 102 and 112 areclosely attached to the user, the wearable mobile devices 100 and 110may measure a numerical range in which the wearable mobile devices 100and 110 are in contact with the user, and determine that the sensorunits 104 and 114 are closely attached to the user when the measurednumerical range satisfies a predetermined standard value. The wearablemobile devices 100 and 110 may recognize whether the bracelets areclosely attached to the user based on the numerical range in which thewearable mobile devices 100 and 110 are in contact with the user. Forexample, when the range in which the wearable mobile devices 100 and 110are in contact with the user is a greater than or equal to 95% of aninternal area of the ring form, the wearable mobile devices 100 and 110may determine that the band portions 102 and 112 are closely attached tothe user.

In another example, the wearable mobile devices 100 and 110 may measurea position at which the wearable mobile devices 100 and 110 are incontact with the user, and may determine that the band portions 102 and112 of the bracelets are closely attached to the user in response to themeasured position corresponds to a predetermined skin area of the user.The wearable mobile devices 100 and 110 may recognize a degree ofcontact with the user based on the position at which the wearable mobiledevices 100 and 110 are in contact with the user. For example, when thewearable mobile devices 100 and 110 are attached to a wrist of the userand move towards a forearm having a relatively greater circumferencethan the wrist, and are positioned on the forearm, the wearable mobiledevices 100 and 110 may determine that the band portions 102 and 112 areclosely attached to the user. The position of the wearable mobiledevices 100 and 110 on the user may be measured by an additional sensorthat may be included in the band portions 102 and 112. A more detaileddescription will be provided hereinafter.

In response to a determination that the wearable mobile devices areclosely attached to the user, the wearable mobile devices 100 and 110may provide the biosignal-based service. The wearable mobile devices 100and 110 may activate the sensor units 104 and 114 after the bandportions 102 and 112 are determined to be closely attached to the user,and may provide the biosignal-based service using a biosignal obtainedthrough the sensor units 104 and 114 being activated.

For example, the band portions 102 and 112 are closely attached to theuser, the wearable mobile devices 100 and 110 may activate a PPG sensorto measure heart rates, and may provide an exercise management serviceassociated with the heart rates as the biosignal-based service.

For another example, in response to the band portions 102 and 112 beingclosely attached to the user, the wearable mobile devices 100 and 110may activate an EMG sensor to measure a biosignal associated with amovement of the user, and may provide a gesture-based control servicefor a home appliance as the biosignal-based service.

For still another example, when the band portions 102 and 112 areclosely attached to the user, the wearable mobile devices 100 and 110may activate an EMG sensor to measure an impedance, and may provide anindividual authentication service associated with the impedance as thebiosignal-based service.

To provide the biosignal-based service, the wearable mobile devices 100and 110 may execute a program for detecting a biosignal from the user ora program using the detected biosignal, and may provide a result outputby the executed program as the biosignal-based service.

Based on the close contact with the user, the wearable mobile devices100 and 110 may automatically execute a predetermined program associatedwith the biosignal, and may provide a result of the measurement of thebiosignal and information about the result based on the execution of theprogram.

In an example, the band portions 102 and 112 of the wearable mobiledevices 100 and 110 may be composed of a hard material that may not beeasily deformed by an external force and thus, the user may not need tointentionally adjust a length of the band portions 102 and 112. Thewearable mobile devices 100 and 110 may refer to a general fact that aforearm may be thicker than a wrist and the wrist may be thinner thanthe forearm, and may allow the user to raise the wearable mobile devices100 and 110 towards the forearm when in need of detecting a biosignaland to lower the wearable mobile devices 100 and 110 towards the wristwhen not in need of detecting the biosignal. Accordingly, the user mayconveniently change wearability of the wearable mobile devices 100 and110.

Also, the wearable mobile devices 100 and 110 may independentlydetermine whether the wearable mobile devices 100 and 110 are closelyattached to an arm of the user and determine whether to provide thebiosignal-based service based on the determination. Accordingly, thewearable mobile devices 100 and 110 may increase a level of convenienceby allowing the user to use the service without requiring an additionaloperation from the user.

FIG. 2 is a diagram illustrating an example of a configuration of awearable mobile device 200.

Referring to FIG. 2, the wearable mobile device 200 includes a bracelethaving a band portion 210, a determiner 220, and a sensor unit 230.Also, the wearable mobile device 200 further includes a controller 240and an output unit 250. The determiner 220 may operate on a processor.

The band portion 210 may detachably attach the wearable mobile device200 to an user 205 by surrounding the user 205. The wearable mobiledevice 200 may be mounted on the user 205 through the band portion 210of the bracelet.

The band portion 210 may include the sensor unit 230 in which at leastone sensor 232 may be disposed at regular intervals. The sensor 232 ofthe wearable mobile device 200 may be positioned such that, when theband portion 210 is attached to the user, the sensor 232 affixed in thesensor unit 230 exposes a sensing surface to contact the user 205. Thesensing surface refers a surface that may be in contact with the user205 and may directly sense a biosignal generated from the user 205. Thesensor 232 may be disposed on the sensing surface. For example, thesensing surface may sense a broad range of biosignals such as abioelectrical/biomagnetic signal, bioimpedance signal, and abiodynamical signal of the user 205.

The band portion 210 of the bracelet may be initially attached to awrist of a user and may be subsequently attached to a forearm of theuser so that the sensing surface on which the sensing unit 230 isdisposed is closely attached to the skin of the forearm by movingtowards the forearm to acquire a biosignal-based service based on anintention of the user. In response to a determination that the sensorunit 230 is closely attached to the user 205, the sensor unit 230 maycollect biosignals from all ranges of muscles of the forearm, which maybe the user 205, through the sensor 232.

The determiner 220 may determine whether the band portion 210 is closelyattached to the user 205 based on a movement of the bracelet duringattachment to the user. The determiner 220 may verify a degree ofcontact between the bracelet and the user 205 and may arrange anenvironment in which the biosignal-based service is selectively providedbased on the verified degree of contact.

The determiner 220 may measure a range or a position at which thebracelet is attached to the user 205, and may determine that thebracelet is closely attached to the user 205 in response to the measuredrange satisfying a predetermined standard value or the measured positioncorresponding to a predetermined skin area of the user 205.

Also, the determiner 220 may determine whether the bracelet is closelyattached to the user 205 through an analog front end of the sensor 232that may be disposed in contact with the user 205. The analog front endmay indicate a front electrode and a rear electrode of the sensor 232that may be responsible for detection.

In response to the analog front end not being in a leadoff state, thedeterminer 220 may determine that the wearable mobile device 200 isclosely attached to the user 205. The determiner 220 may determinewhether the wearable mobile device 200 is closely attached to the user205 by verifying the leadoff state in which the wearable mobile device200 has a modest degree of separation from the user 205 and the analogfront end is not able to optimally collect signals from the user 205.For example, at a point in time when the analog front end is placed intocontact with the user 205, the analog front end may send a signal to theuser 205. When the analog front end receives a return of the signal fromthe user 205, the determiner 220 may determine that the analog front endis in an actual contact with the user 205 and not in the leadoff state;thus, the determiner 220 may determine that the wearable mobile device200 is closely attached to the user 205.

The determiner 220 may determine whether the wearable mobile device 200is closely attached to the user 205 based on a microcurrent sent fromthe analog front end to the user 205. When an impedance measured basedon a return of the sent microcurrent satisfies a predetermined value,the determiner 220 may determine that the wearable mobile device 200 isclosely attached to the user 205. For example, when the analog front endsends the microcurrent to the user 205 at a point in time when theanalog front end is placed into contact with the user 205, thedeterminer 220 may calculate the impedance based on the microcurrentreturning from the user 205, and may determine that the wearable mobiledevice 200 is closely attached to the user 205 by identifying that thecalculated impedance exceeds the predetermined value, for example, 100milliohms (mΩ).

The determiner 220 may determine whether the wearable mobile device 200is closely attached to the user 205 using an additional sensor 234 thatmay be additionally included in the band portion 210. The additionalsensor 234 may include a temperature sensor used to sense a temperatureemitted from the user 205, a force sensor used to sense a pressureapplied by the user 205, an illuminance sensor used to detect brightnessin the user 205 based on a degree of contact, and the like. Theadditional sensor 234 may be one or more sensors used to determine adegree of contact apart from the detection of the biological signalsused to provide the biosignal-based service.

When the additional sensor 234 enters an operating state based on aposition at which the band portion 210 of bracelet is attached to theuser 205, the determiner 220 may determine that the sensor unit 230 isclosely attached to the user 205. For example, the force sensor of theadditional sensor 234 may detect an increasing pressure from the user205 based on a change in the position of the band portion 210 movingfrom a wrist to a forearm, and the determiner 220 may recognize theoperating state of the force sensor. Accordingly, the determiner 220 maydetermine that the sensor unit 230 is closely attached to the user 205.

The determining of whether the sensor unit 230 is closely attached tothe user 205 by the determiner 220 will be further described withreference to FIGS. 3A and 3B.

FIGS. 3A and 3B are diagrams illustrating examples of determiningwhether a bracelet is closely attached to an object.

Referring to FIG. 3A, an electrode 340 may be verified to be in a directcontact with the user 330 through leadoff detection 314 in an analogfront end 312 of a sensor 310 or impedance measurement 316.

The electrode 340 may be used along with another electrode 340 that mayobtain a biosignal from the object 330. Also, the electrode 340 may beused for the leadoff detection 314 or the impedance measurement 316 byobtaining a signal or a microcurrent form the user 330.

The electrode 340 may operate by classifying a point in time at whichthe leadoff detection 312 or the impedance measurement 316 is performedand a point in time at which a biosignal is obtained. The electrode 340may be used to determine whether the bracelet is in contact with theuser 330 by performing the leadoff detection 312 or the impedancemeasurement 316 using a relatively small amount of power prior toprovision of the biosignal-based service. Also, the electrode 340 may beused to obtain the biosignal from the user 330 using a relativelygreater amount of power after the bracelet is determined to be incontact with the user 330.

In an example of performing the leadoff detection 314, an analog frontend 312 may send a signal to the user 330 through a front electrode ofthe electrode 340. In the event that the signal returns to a rearelectrode of the electrode 340 via the user 330, the electrode 340 maybe estimated to be in a lead-on state in which the electrode 340 is in adirect contact with the user 330. In response to the electrode 340 beingestimated to be in a lead-on state, the determiner 220 may determinethat the bracelet is closely attached to the user 330 and allow theelectrode 340 to obtain the biosignal; thus, a wearable mobile devicemay establish a condition under which a biosignal-based service may beprovided.

Conversely, in the event that the signal sent from the front electrodeof the electrode 340 does not return to the rear electrode of theelectrode 340 after a predetermined period of time elapses, theelectrode 340 may be estimated to be in a lead-off state in which theelectrode 340 is not in contact with the user 330. The determiner 220may determine that the bracelet is not closely attached to the user 330and may allow a service unrelated to the biosignal to be provided to theuser.

In another example of performing the leadoff detection 314, thedeterminer 220 may analyze a waveform of a biosignal obtained throughthe electrode 340 of the analog front end 312, and determine whether theelectrode 340 is in an exact contact with the user 330 or separated fromthe user 330. For example, in the event that a curve of the waveform ofthe biosignal changes drastically at an arbitrary point in time, thedeterminer 220 may determine, at a software level, that the electrode340 is in the lead-off state in which the electrode 340 is separatedfrom the user 330.

Also, in an example of performing the impedance measurement 316, theanalog front end 312 may send a microcurrent to the user 330 through theelectrode 340 and receive a return of the microcurrent from the user330. Subsequently, the determiner 220 may calculate an impedance withrespect to the user 330 based on the returned microcurrent, and maycompare the calculated impedance to a predetermined value. In the eventthat the calculated impedance exceeds the predetermined value as aresult of the comparison, the determiner 220 may determine that thesensor 310 is closely attached to the user 330 and may allow theelectrode 340 to obtain the biosignal; thus, the wearable mobile devicemay prepare an environment in which the biosignal-based service isprovided.

Conversely, in response to a determination that the calculated impedancedoes not satisfy the predetermined value as a result of the comparison,the determiner 220 may determine that the bracelet is not closelyattached to the user 330 and may allow a service unrelated to thebiosignal to be provided.

FIG. 3B is a diagram illustrating an example of a method of determiningwhether a bracelet is closely attached to the user 330 by an additionalsensor 320.

Referring to FIG. 3B, the additional sensor 320 may be additionallyincluded in the bracelet for detecting whether a biosignal detectionsensor is closely attached to the user 330. The additional sensor 320may include a force sensor 322, a temperature sensor 324, and anilluminance sensor 326.

The force sensor 322 may detect changes in pressure from the user 33based on a position at which the bracelet is attached to the user 330and may estimate whether the bracelet is closely attached to the user330. For example, in the event that the force sensor 322 detects anincrease in pressure “SW_ON” and an operating state of the force sensor322 is recognized, the determiner 220 may estimate that the position atwhich the bracelet is attached to the user 330 changes from a wrist to aforearm and determine that the bracelet is closely attached to the user330. Conversely, in the event that the force sensor 322 detects adecrease in pressure “SW_OFF” and the operating state of the forcesensor 322 is not recognized, the determiner 220 may estimate that theposition at which the bracelet is attached to the user 330 changes fromthe forearm to the wrist and determine that the bracelet is looselyattached to the user 330.

The temperature sensor 324 may detect changes in temperature emittedfrom the user 330 based on the position at which the bracelet isattached to the user 330 and estimate whether the bracelet is closelyattached to the user 330. For example, when the temperature sensor 324detects an increase in temperature “SW_ON” to be greater than or equalto a threshold temperature, for example, 31° C. indicating a temperatureof skin, and an operating state of the temperature sensor 324 isrecognized, the determiner 220 may estimate that the position at whichthe bracelet is attached to the user 330 moves towards the forearmhaving a relatively greater circumference and determine that thebracelet is closely attached to the user 330. Conversely, when thetemperature sensor 324 detects a decrease in temperature “SW_OFF” to beless than the threshold temperature and the operating state of thetemperature sensor 324 is not recognized, the determiner 220 mayestimate that the position at which the bracelet is attached to the user330 moves towards the wrist having a relatively smaller circumferenceand determine that the bracelet is loosely attached to the user 330.

Similarly, the illuminance sensor 326 may detect changes in brightnessin the user 330 based on a degree of contact between the bracelet andthe user 330 and estimate whether the bracelet is closely attached tothe user 330. For example, when the illuminance sensor 326 detects adecrease in brightness “SW_ON” to be less than a threshold illuminance,for example, 10 lux (lx) indicating an illuminance of skin, and anoperating state of the illuminance sensor 326 is recognized, thedeterminer 220 may estimate that the position at which the bracelet isattached to the user 330 moves towards the forearm from the wrist anddetermine that the bracelet is closely attached to the user 330.Conversely, when the illuminance sensor 326 detects an increase inilluminance “SW_OFF” to be greater than or equal to the thresholdilluminance and the operating state of the illuminance sensor 326 is notrecognized, the determiner 220 may estimate that the position at whichthe bracelet is attached to the user 330 moves towards the wrist fromthe forearm and determine that the bracelet is loosely attached to theuser 330.

Thus, the determiner 220 may determine whether the bracelet is closelyattached to the user 330 in conjunction with the operating state of theadditional sensor 320.

Referring back to FIG. 2, when the sensor unit 230 includes the sensor232 and is determined to be closely attached to the user 205, the sensorunit 230 may be activated and detect a biosignal from the user 205. Thesensor unit 230 may be in contact with the user 205 and monitor abiosignal generated by the user 205.

The user 205 may indicate a muscle of an organism from which a biosignalis required to be measured, for example, a wrist muscle and a forearmmuscle.

The sensor unit 230 may include the sensor 232, for example, an ECGsensor, a PPG sensor, an impedance sensor, an EMG sensor, an irisrecognition sensor, and a fingerprint recognition sensor, that maycollect signals from the user 205. Thus, the sensor unit 230 may detectvarious biosignals generated from the muscle using the sensor 232.

The biosignals may include, for example, a bioelectric/biomagneticsignal, a bioimpedance signal, a biomechanical signal, and the like thatmay be generated from the muscle.

Also, the sensor unit 230 may detect a gesture performed in associationwith the user 205 based on a pattern of a detected biosignal. Forexample, the sensor unit 230 may distinguish a difference in the patternof the detected biosignal and differently recognize a gesture ofclenching a first and a gesture of folding a finger.

To detect the biosignals, the sensor unit 230 may identify an activatedsensor of the sensor 232 based on a position at which the wearablemobile device 200 is closely attached to the user 205 and detect thebiosignals using the identified sensor. For example, when the wearablemobile device 200 is determined to be closely attached to an upper arm,the sensor unit 230 may activate a biometric sensor of the sensor 232and perform an individual user authentication. Also, when the wearablemobile device 200 is determined to be closely attached to a lower arm,the sensor unit 230 may activate an EMG sensor of the sensor 232 andobtain an EMG signal to recognize a gesture of the user. Similarly, whenthe wearable mobile device 200 is determined to be closely attached to awrist, the sensor unit 230 may activate a PPG sensor and measure heartrates of the user.

The wearable mobile device 200 may selectively provide a biosignal-basedservice by determining whether the wearable mobile device 200 is closelyattached to the user 205.

To perform the foregoing, the wearable mobile device 200 may furtherinclude the controller 240.

When the wearable mobile device 200 is determined to be closely attachedto the user 205, the controller 240 may execute a program associatedwith the biosignals or adjust a system environment to be a predeterminedvalue. The controller 240 may automatically execute a program fordetecting the biosignals from the user 205 or a predetermined programusing the detected biosignals.

For example, when the wearable mobile device 200 is determined to beclosely attached to the user 205, the controller 240 may automaticallychange a configuration of the wearable mobile device 200 to which thebiosignal-based service is provided.

Also, when the wearable mobile device 200 is closely attached to theuser 205, the controller 240 may automatically execute an applicationfor analyzing the biosignals detected through the activated sensor unit230 or automatically terminate an application without having a directconnection to the biosignals.

When the wearable mobile device 200 is not closely attached to the user205, the controller 240 may control the executed program to be suspendedor restore the adjusted system environment to be an original value.Also, when the wearable mobile device 200 is not closely attached to theuser 205, the controller 240 may control the sensor unit 230 to beinactivated and to suspend the detection of the biosignals.

The wearable mobile device 200 may further include the output unit 250that may output a result of the determining of whether the wearablemobile device 200 is closely attached to the user 205.

When the wearable mobile device 200 is closely attached to the user 205,the output unit 250 may provide, as the biosignal-based service, theresult output by the program associated with the biosignals andautomatically executed. When the wearable mobile device 200 is closelyattached to the user 205, the output unit 250 may provide a result ofdetecting the biosignals and information about the execution of theprogram.

For example, when the wearable mobile device 200 is closely attached tothe user 205, the output unit 250 may output, as the biosignal-basedservice, an exercise management service associated with heart ratesmeasured by the PPG sensor.

For another example, the output unit 250 may output, as thebiosignal-based service, a gesture control service for a home applianceusing the biosignals based on a movement of the user 205.

For still another example, the output unit 250 may output, as thebiosignal-based service, an individual authentication service associatedwith the impedance measured by the EMG sensor.

Also, when the wearable mobile device 200 is closely attached to theuser 205, the output unit 250 may output feedback indicating an abilityto detect a biosignal through one of vision, vibration, and sound.Conversely, when the wearable mobile device 200 is not closely attachedto the user 205, the output unit 250 may output feedback indicating aninability to detect a biosignal through one of vision, vibration, andsound.

The wearable mobile device 200 may automatically provide a suitableservice associated with a biosignal by allowing the user to simplydetermine whether the band portion 210 of the bracelet is to be looselyor tightly attached to the forearm. Accordingly, the wearable mobiledevice 200 may provide a high level of convenience to the user.

When the user loosely attaches the band portion 210 of the bracelet, thewearable mobile device 200 may automatically cease detection of abiosignal using the sensor unit 230. Accordingly, the wearable mobiledevice 200 may adequately control use of a large amount of power thatmay be consumed due to a conventional method of permanently detecting abiosignal.

An operation of the wearable mobile device 200 will be further describedhereinafter.

FIG. 4 is a flowchart illustrating an example of a method of using thewearable mobile device 200 of FIG. 2 to selectively detect a biosignal.

In 410, the band portion 210 of the wearable mobile device 200 isattached to the user 205 by surrounding a body part of the user 205.Operation 410 may allow the wearable mobile device 200 to be worn by theuser 205, a target to be measured, using the bracelet 210.

The bracelet 210 may include the at least one sensor 232 that may bedisposed at regular intervals in the sensor unit 230. When the bracelet210 is being attached to the user 205, the sensor 232 in the sensor unit230 may be fixed to allow a sensing surface to be in contact with theuser 205. The sensing surface may refer to a surface on which the sensor232 that may directly detect a biosignal generated from the user 205while being in direct contact with the user 205 are disposed. Forexample, the wearable mobile device 200 may detect a wide range ofbiosignals, for example, a bioelectric/biomagnetic signal, abioimpedance signal, and a biodynamical signal, in association with theuser 205 through the sensor unit 230.

The band portion 210 may be initially attached to a wrist of a user, andmove towards a forearm of the user to acquire a biosignal-based servicebased on an intention of the user, so that the sensing surface on whichthe sensor unit 230 is disposed may be closely attached to skin of theforearm. When the wearable mobile device 200 is determined to be closelyattached to the body of the user 205, the sensor unit 230 may collectbiosignals through the sensor 232 of the sensing unit 230 from allranges of a forearm muscle, which may be the body part of the user 205to which the wearable mobile device 200 is attached.

In 420, the wearable mobile device 200 may determine whether thewearable mobile device 200 is closely attached to the user 205 based ona movement of the wearable mobile device 200 during attachment of thewearable mobile device 200 to the user 205. Operation 420 may be aprocess of preparing an environment in which the biosignal-based serviceis selectively provided after a degree of contact between the sensorunit 250 on the band portion 210 and the user 205 is verified.

In 420, the wearable mobile device 200 may measure a range or a positionat which the band portion 210 of the bracelet is in contact with theuser 205, and may determine that the sensor unit 250 of the band portion210 is closely attached to the user 205 in response to the measuredrange satisfying a predetermined standard value or the measured positioncorresponding to a predetermined skin area in the user 205.

In an example, the wearable mobile device 200 may determine whether theband portion 210 of the bracelet is closely attached to the user 205through an analog front end of the sensor 232 that may be in contactwith the user 205. The analog front end may indicate a front electrodeand a rear electrode of the sensor 232 that may be responsible fordetection.

When the analog front end is not in a leadoff state, the wearable mobiledevice 200 may determine that the band portion 210 is closely attachedto the user 205. The wearable mobile device 200 may determine that thewearable mobile device 200 is closely attached to the user 205 byverifying the leadoff state in which the wearable mobile device 200 isslightly separated from the user 205 and the analog front end is notable to optimally collect signals. For example, the analog front end maysend a signal to the user 205 at a point in time when the wearablemobile device 200 is attached to the user 205. When the analog front endreceives a return of the signal from the user 205, the wearable mobiledevice 200 may determine that the analog front end is in an actualcontact with the user 205 and not in the leadoff state. Simultaneously,the wearable mobile device 200 may determine that the wearable mobiledevice 200 is closely attached to the user 205.

In another example, the wearable mobile device 200 may determine whetherwearable mobile device 200 is closely attached to the user 205 using amicrocurrent sent from the analog front end to the user 205. When animpedance measured based on the return of the sent microcurrentsatisfies a predetermined value, the wearable mobile device 200 maydetermined that the wearable mobile device 200 is closely attached tothe user 205. For example, in response to the microcurrent sent from theanalog front end to the user 205 at a point in time when the analogfront end is placed into contact with the user 205, the wearable mobiledevice 200 may calculate the impedance based on the microcurrentreturned from the user 205, and determine that the wearable mobiledevice 200 is closely attached to the user 205 by identifying that thecalculated impedance exceeds the predetermined standard value, forexample, 100 mΩ.

In still another example, the wearable mobile device 200 may determinethat wearable mobile device 200 is closely attached to the user 205using the additional sensor 234 that may be additionally included in theband portion 210 of the wearable mobile device 200. The additionalsensor 234 may include a temperature sensor used to detect a temperatureemitted from the user 205, a force sensor used to detect pressureapplied by the user 205, an illuminance sensor used to detect brightnessin the user 205 based on a degree of contact, and the like.

When the additional sensor 234 enters an operating state, the wearablemobile device 200 may determine that wearable mobile device 200 isclosely attached to the user 205, based on a position at which thewearable mobile device 200 is attached to the user 205. For example,when the position of the wearable mobile device 200 moves from the wristto the forearm, the force sensor of the additional sensor 234 may detectan increase in pressure from the user 205, and the wearable mobiledevice 200 determine that the wearable mobile device 200 is closelyattached to the user 205 by recognizing the operating state of the forcesensor.

In 430, when the wearable mobile device 200 is determined to be closelyattached to the user in operation 420 (in a YES direction), the wearablemobile device 200 activates the sensor 232 in the sensor unit 230 anddetects a biosignal from the user 205. Operation 430 may be a process ofmonitoring a biosignal generated from the user 205 during attachment ofthe wearable mobile device 200 to the user 205.

The user 205 may indicate a muscle of an organism from which a biosignalis required to be detected, for example, a wrist muscle and a forearmmuscle.

The sensor unit 230 may include the sensor 232 such as an ECG sensor, aPPG sensor, an impedance sensor, an EMG sensor, an iris recognitionsensor, and a fingerprint recognition sensor, and the like, and detectvarious biosignals generated from the muscle using the sensor 232.

The biosignals may include a bioelectric/biomagnetic signal, abioimpedance signal, a biomechanical signals, and the like, generatedfrom the muscle.

Also, the wearable mobile device 200 may detect a gesture associatedwith the user 205 based on a pattern of a detected biosignal through thesensor unit 230. For example, the wearable mobile device 200 maydistinguish a difference in the pattern of the detected biosignal, anddifferently detect a gesture of clenching a first by the user or agesture of folding a finger.

To detect a biosignal, the wearable mobile device 200 may identify anactivated sensor among the sensor 232 based on a position at which thewearable mobile device 200 is closely attached to the user 205, anddetect the biosignal using the identified sensor. For example, when thewearable mobile device 200 is determined to be closely attached to anupper arm, the wearable mobile device 200 may activate a biometricsensor of the sensor 232 and perform an individual user authentication.Also, when the wearable mobile device 200 is determined to be closelyattached to a lower arm, the wearable mobile device 200 may activate anEMG sensor of the sensor 232 and obtain an EMG signal to recognize agesture by the user. Similarly, when the wearable mobile device 200 isdetermined to be closely attached to a wrist, the wearable mobile device200 may activate a PPG sensor of the sensor 232 and measure heart ratesof the user.

In 440, the wearable mobile device 200 provides a selectivebiosignal-based service when the wearable mobile device 200 isdetermined to be closely attached to the user 205.

In 440, the wearable mobile device 200 executes a program associatedwith the biosignal or adjusts a system environment to be a predeterminedvalue. The wearable mobile device 200 may automatically execute aprogram for detecting a biosignal from the user 205 or a predeterminedprogram using the detected biosignal.

For example, when the wearable mobile device 200 is determined to beclosely attached to the user 205, the wearable mobile device 200 mayautomatically change a configuration of the wearable mobile device 200to be a configuration in which the biosignal-based service is provided.

Also, when the wearable mobile device 200 is determined to be closelyattached to the user 205, the wearable mobile device 200 mayautomatically execute an application for analyzing the biosignaldetected through the activated sensor of the sensor 232 in the sensorunit 230 or automatically terminate an application that may not bedirectly related to the biosignal.

Further, the wearable mobile device 200 may output a result of thedetermining of whether the wearable mobile device 200 is closelyattached to the user 205. The wearable mobile device 200 may provide, asthe biosignal-based service, a result output by the program associatedwith the biosignal that may be automatically executed based on theresult of the determining.

For example, the wearable mobile device 200 may output, as thebiosignal-based service, an exercise management service associated withheart rates measured by the PPG sensor based on the result of thedetermining.

For another example, the wearable mobile device 200 may output, as thebiosignal-based service, a gesture control service for a home applianceusing a biosignal based on a movement of the user 205.

For still another example, the wearable mobile device 200 may output, asthe biosignal-based service, an individual authentication serviceassociated with an impedance to be measured by the EMG sensor.

Also, when the wearable mobile device 200 is closely attached to theuser 205, the wearable mobile device 200 may output feedback indicatingan ability to measure a biosignal through one of vision, vibration, andsound. Conversely, when the wearable mobile device 200 is not closelyattached to the user 205, the output unit 250 of the wearable mobiledevice 200 may output feedback indicating an inability to measure thebiosignal through one of vision, vibration, and sound.

In 450, when the wearable mobile device 200 is determined not to beclosely attached to the user 205 in operation 420 (in a NO direction),the wearable mobile device 200 may provide a service unrelated to abiosignal. Operation 450 may be a process of providing a communicationservice with a connected terminal or a service that may not be directlyrelated to the biosignal.

For example, when the wearable mobile device 200 is not closely attachedto the user 205, the wearable mobile device 200 may provide visualinformation about a quantity of terminal utilization that may beverified by an accelerometer.

Also, when the wearable mobile device 200 is not closely attached to theuser 205, the wearable mobile device 200 may control the executedprogram to stop or restore the adjusted system environment to be anoriginal value, as the biosignal-based service in operation 440.

When the wearable mobile device 200 is not closely attached to the user205, the wearable mobile device 200 may control the sensor 232 in thesensor unit 230 to be in an inactivated state and to cease detection ofa biosignal.

The wearable mobile device 200 may automatically provide, to a user, asuitable service associated with a biosignal of the user by allowing theuser to simply determine whether the wearable mobile device 200 is to beloosely attached to a wrist or tightly attached to a forearm and thus, ahigh level of convenience may be provided to the user.

When the user loosely attaches the wearable mobile device 200, thewearable mobile device 200 may automatically stop allowing the sensorunit 230 to measure a biosignal. Thus, the wearable mobile device 200may adequately control use of a vast amount of power consumed forpermanent measurement of biosignals in conventional usage.

The units described herein may be implemented using hardware componentsand software components. For example, the hardware components mayinclude microphones, amplifiers, band-pass filters, audio to digitalconvertors, and processing devices. A processing device may beimplemented using one or more general-purpose or special purposecomputers, such as, for example, a processor, a controller and anarithmetic logic unit, a digital signal processor, a microcomputer, afield programmable array, a programmable logic unit, a microprocessor orany other device capable of responding to and executing instructions ina defined manner. The processing device may run an operating system (OS)and one or more software applications that run on the OS. The processingdevice also may access, store, manipulate, process, and create data inresponse to execution of the software. For purpose of simplicity, thedescription of a processing device is used as singular; however, oneskilled in the art will appreciated that a processing device may includemultiple processing elements and multiple types of processing elements.For example, a processing device may include multiple processors or aprocessor and a controller. In addition, different processingconfigurations are possible, such a parallel processors.

The software may include a computer program, a piece of code, aninstruction, or some combination thereof, to independently orcollectively instruct or configure the processing device to operate asdesired. Software and data may be embodied permanently or temporarily inany type of machine, component, physical or virtual equipment, computerstorage medium or device, or in a propagated signal wave capable ofproviding instructions or data to or being interpreted by the processingdevice. The software also may be distributed over network coupledcomputer systems so that the software is stored and executed in adistributed fashion. The software and data may be stored by one or morenon-transitory computer readable recording mediums. The non-transitorycomputer readable recording medium may include any data storage devicethat can store data which can be thereafter read by a computer system orprocessing device. Examples of the non-transitory computer readablerecording medium include read-only memory (ROM), random-access memory(RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storagedevices. Also, functional programs, codes, and code segments thataccomplish the examples disclosed herein can be easily construed byprogrammers skilled in the art to which the examples pertain based onand using the flow diagrams and block diagrams of the figures and theircorresponding descriptions as provided herein.

As a non-exhaustive illustration only, a terminal or device describedherein may refer to mobile devices such as a cellular phone, a personaldigital assistant (PDA), a digital camera, a portable game console, andan MP3 player, a portable/personal multimedia player (PMP), a handhelde-book, a portable laptop PC, a global positioning system (GPS)navigation, a tablet, a sensor, and devices such as a desktop PC, a highdefinition television (HDTV), an optical disc player, a setup box, ahome appliance, and the like that are capable of wireless communicationor network communication consistent with that which is disclosed herein.

While this disclosure includes specific examples, it will be apparent toone of ordinary skill in the art that various changes in form anddetails may be made in these examples without departing from the spiritand scope of the claims and their equivalents. The examples describedherein are to be considered in a descriptive sense only, and not forpurposes of limitation. Descriptions of features or aspects in eachexample are to be considered as being applicable to similar features oraspects in other examples. Suitable results may be achieved if thedescribed techniques are performed in a different order, and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner and/or replaced or supplemented by othercomponents or their equivalents. Therefore, the scope of the disclosureis defined not by the detailed description, but by the claims and theirequivalents, and all variations within the scope of the claims and theirequivalents are to be construed as being included in the disclosure.

What is claimed is:
 1. A method of measuring a biosignal, the methodcomprising: determining whether an attached wearable mobile device isclosely attached to a user or loosely attached to the user; andproviding a biosignal-based service in response to the wearable mobiledevice being determined to be closely attached to the user and providinga non-biosignal-based service to the user in response to the wearablemobile device being determined to be loosely attached to the user,wherein the determining comprises: measuring a range or a position atwhich the wearable mobile device contacts the user; determining that thewearable mobile device is closely attached to the user in response tothe measured range satisfying a standard value or in response to themeasured position corresponding to a skin area of the user; anddetermining that the wearable mobile device is loosely attached to theuser when the wearable mobile device is located at a wrist area of theuser; and wherein the standard value and the skin area of the usercorrespond to the wearable mobile device being positioned at a skin areaof the user that has greater circumference than a wrist area of theuser.
 2. The method of claim 1, wherein the providing of thebiosignal-based service comprises: executing a program for measuring abiosignal from the user or a program that uses a measured biosignal; andproviding a result from the executed program as the biosignal-basedservice.
 3. A wearable mobile device method, the method comprising:determining whether a bracelet, as a wearable mobile device, is closelyattached to a user or loosely attached to the user based on apositioning of the bracelet while the bracelet is attached to the user;and sensing a biosignal from the user by activating a sensor, configuredto sense the biosignal from the user, of the bracelet in response to thebracelet being determined to be closely attached to the user, whereinthe determining comprises: measuring a range or position at which thebracelet contacts the user; and determining that the bracelet is closelyattached to the user in response to the measured range satisfying astandard value or in response to the measured position corresponding toa skin area of the user; and determining that the bracelet is looselyattached to the user when the bracelet is located at a wrist area of theuser; and wherein the standard value and the skin area of the usercorrespond to the wearable mobile device being positioned at a skin areaof the user that has a greater circumference than a wrist area of theuser.
 4. The method of claim 3, wherein the determining comprises:determining that the bracelet is closely attached to the user inresponse to an analog front end of the sensor being in a lead-on stateand determining that the bracelet is loosely attached to the user inresponse to the analog front end of the sensor being in a lead-offstate, the analog front end of the sensor being arranged in the braceletso that the lead-on state indicates that the sensor is in contact with abody portion of the user sufficient to sense the biosignal and thelead-off state indicates that that the sensor is not in contact with thebody portion sufficient to sense the biosignal.
 5. The method of claim3, wherein the determining comprises: sending a microcurrent to the userthrough the analog front end of the sensor; and determining that thebracelet is closely attached to the user in response to an impedancemeasured based on a return of the sent microcurrent satisfying thestandard value and determining that the bracelet is loosely attached tothe user in response to the measured impedance not satisfying thestandard value.
 6. The method of claim 3, wherein the determiningfurther comprises: determining that the bracelet is closely attached tothe user in response to an additional sensor of the bracelet, fordetermining whether the bracelet is closely attached or loosely attachedto the user, entering an operating state based on a body position atwhich the bracelet is attached to the user.
 7. The method of claim 3,wherein the sensing comprises: identifying which sensors of the braceletto activate to sense respective biosignals based on the positioning ofthe bracelet while the bracelet is attached to the user; and sensing therespective biosignals.
 8. The method of claim 3, further comprising: inresponse to determining that the bracelet is closely attached to theuser, executing a program associated with the biosignal or adjusting asystem environment to be a predetermined value; and in response todetermining that the bracelet is loosely attached to the user,deactivating the sensor.
 9. The method of claim 3, further comprising:outputting a result of the determining of whether the bracelet isclosely or loosely attached to the user.
 10. A wearable mobile device,comprising: a bracelet, as the wearable mobile device, configured to beattached to a user by at least partially surrounding a body portion ofthe user; a determiner configured to determine whether the bracelet isclosely attached to the user or loosely attached to the user based on apositioning of the bracelet while the bracelet is attached to the user;and a sensor unit comprising a sensor configured to sense a biosignalfrom the user subsequent to activation of the sensor in response to thedeterminer determining that the bracelet is closely attached to theuser, wherein the determiner is configured to measure a range or aposition at which the wearable mobile device contacts the user; todetermine that the wearable mobile device is closely attached to theuser in response to the measured range satisfying a standard value or inresponse to the measured position corresponding to a skin area of theuser; and to determine that the wearable mobile device is looselyattached to the user when the wearable mobile device is located at awrist area of the user; and wherein the standard value and the skin areaof the user correspond to the wearable mobile device being positioned ata skin area of the user that has a greater circumference than the wristarea of the user.
 11. The device of claim 10, wherein the sensorincludes an analog front end arranged in the bracelet so that a lead-onstate of the sensor indicates that the sensor is in contact with a bodyportion of the user sufficient to sense the biosignal and so that alead-off state of the sensor indicates that that the sensor is not incontact with the body portion sufficient to sense the biosignal, andwherein the determiner is configured to determine that the bracelet isclosely attached to the user in response to the analog front end beingin the lead-on state and to determine that the bracelet is looselyattached to the user in response to the analog front end being in thelead-off state.
 12. The device of claim 10, wherein the determiner isconfigured to control the analog front end of the sensor to send amicrocurrent to the user, and wherein the determiner is configured todetermine that the bracelet is closely attached to the user in responseto an impedance measured based on a return of the sent microcurrentsatisfying the standard value and determining that the bracelet isloosely attached to the user in response to the measured impedance notsatisfying the standard value.
 13. The device of claim 10, wherein thebracelet further comprises an additional sensor for determining whetherthe bracelet is closely attached or loosely attached to the user, andwherein the determiner is configured to determine that the bracelet isclosely attached to the user in response to the additional sensor beingactivated based on a body position at which the bracelet is attached tothe user.
 14. The device of claim 10, wherein the sensor unit isconfigured to selectively activate one or more sensors to senserespective biosignals based on the positioning of the bracelet while thebracelet is attached to the user and to sense the respective biosignals.15. The device of claim 10, further comprising: a controller configuredto, in response to the bracelet being determined to be closely attachedto the user, execute a program associated with the biosignal or adjust asystem environment to be a predetermined value, and, in response to thebracelet being determined to be loosely attached to the user, deactivatethe sensor.
 16. The device of claim 10, further comprising: an outputunit configured to output a result of the determining of whether thebracelet is closely or loosely attached to the user.
 17. The method ofclaim 1, further comprising deactivating sensors of the wearable mobiledevice configured to sense a biosignal from the user in response to thewearable mobile device being determined to be loosely attached to theuser.
 18. The method of claim 3, further comprising providing abiosignal-based service to the user in response to the bracelet beingdetermined to be closely attached to the user and providing onlynon-biosignal-based services to the user in response to the braceletbeing determined to be loosely attached to the user.
 19. The method ofclaim 18, further comprising deactivating the sensor in response to thebracelet being determined to be loosely attached to the user.
 20. Thedevice of claim 10, further comprising a controller to control aproviding of a biosignal-based service to the user in response to thebracelet being determined to be closely attached to the user andproviding only non-biosignal-based services to the user in response tothe bracelet being determined to be loosely attached to the user. 21.The device of claim 20, wherein the controller is configured to controla deactivation of the sensor in response to the determiner determiningthat the bracelet is loosely attached to the user.